Well-boring tool



S. TOTH WELL BORING TOOL.

APPLICATION FILED MAR |I.19|9 1,347,469. Patented July 20, 1920.

z E E A 25 7 /5 -36 /0 2 J A J 0" /a r 51 25 I 24 /e /2 9 /6 /7 26 i i 5 I 27 23 2a INVENTOR K961677672 ZZZZ I ATTORNEY UNITED STATES STEVE}; TOTH, OF LOS ANGELES, CALIFORNIA.

WELL-BORING TOOL.

Application filed March 11. 1919.

To 0/] 11-1101 it may POINT/'11.

lie it known that I, S'rnvi-zx Turn, a citizen of the I'nited States. residing at Los Angeles. in the county of Los Angeles and State of California. have invented new and useful lm movements in \Vell-Iioring' Tools, of whlch the followinr is a specification.

This invention re ates to well boring tools and pertains especially to tools of the underrcamer type.

In the boring of wells, tools of both the revolving and 1'e(.-ipro'ating type are employed to drill the well hole in advance of the well casing. which is lowered into the bore following the tool as it advances in the boring operation. It is necessary to bore the well hole of a diameter not less than the outside diameter of the casing sothat said casing may follow the tool. and in order that this may be accomplished it is necessary that the jaws of the tool shall be allowed to spread to a distance of not less than the outside diameter of the well casing.

In the boring operation it becomes necessary to frequently resharpen the jaws of the tooL due to the nature of the work and the varying conditions of the earth, and in order that the tool may be readily removed from the well without disturbing the well casing. provision is made to permit the jaws of the tool to collapse to a distance sufiicient to enable the same to be drawn through the bore of the well tubing.

The object of my invention is to provide a well boring tool. which will accomplish the foregoing recited requirements, and which may be operated to both expand and contract the boring jaws with the least possible dilliclllty.

A further object of my invention is to provide a well boring tool. whereby the jaws of the same may be operated to expand and contract by fluid under pressure, and controlled at the mouth of the well.

Other objects of my invention will ap )ear in the following description and will he pointed out in the claim.

I have illustrated an embodiment of my invention in the accompanying drawings. in all ich Figure l is a vertical section of a well bore and ea ing showing my improved tool in operative boring" position.

l ig. J is a similar view to Fig. l showing the tool uilh the jaws collapsed and in the all of being a it hdrawn from the well casing.

Specification of Letters Patent.

atentcd J My 20. 1920.

Serial No. 281.928.

Fig. 3 is an enlarged transverse section of the tool taken on the line 3-3 of Fig. L

Fig. 4 is a side elevation of the lower end? of the tool.

I have shown my invention as applied to the rcciprtu'ating type of tool which more specifically comprises the drill stock 7. adapted to 'ria'iprocate within the well casing 8 which is disposed in the well bore 9. The stock 7 is preferably of cylindrical form and is provided with the centrally disposed annular bore 10 extending from the top to a point approximately midway of its length and communicating with the enlarged annular bore 11 which extends downwardly to the bottom of the stock.

The bottom of the stock T is provided with oppositely disposed grooves 12 and 13 in which are disposed respectively the cutting jaws 14 and 15. which are loosely pivoted at their upper ends on the pivotal pins 16 and 17 which are secured in the wall of the stock 7.

The jaws l4 and 15 are provided with the cutting points 18 and 1t) and the outwardly inclined edges 20 and 21. said edges being adapted to engage with the lower iuner edges of the wel casing 8 when the tool is drawn upwardly through said casing. The jaws 14 and 15 are also provided with the shoulders 22 and 23 adapted to engage with the lower edge of the stock 7 to re ceive the thrust when in action, the perforations 24 and 25 in the upper'ends of said jaws, through which the pivotal pins 16 and 17 pass, being of larger diameter than said pins. It will be seen by this construction that the pivotal pins are relieved of all strain and serve only to hold thejaws in proper relation to the stock and as a hin e upon which said jaws may swing inwardT' and outwardly as desired.

The jaws 14 and l are also provided with inwardly inclined surfaces 26 and 27 between which is interposed the conical end 28, of an annular piston 29, adapted to slide in the bore 11 of the stock 7.

The stock 7 is provided atv its upper end with the threaded portion 30 to which is threaded the extension tube 31. which is provided at its upper end with the threaded plug 32. said plug having an eye 33 to which is secured one end of a cable 34. The plug 3:2 is also provided with a boss 2K5 adapted to receive one end-of the flexible tube :56,' the opposite end of said tube leading to a source of fluid under pressure supply (not shown). A passage 37 arranged in the plug 32 opens communication between the extension tube 31 and the flexible tube 36.

The stock 7 has arranged in its side the relief valve 38 which is adapted to open communication between the passage 10 and the atmosphere, the operation and purpose of which will be hereinafter explained, and comprises a seat 39, arranged in the stock 7. the valve head 40 having a stem -11. which engages in the guide 42 arranged in the plug 43 threaded into the stock 7, and interposeil between the valve head -10 and the plug 43. and surrounding the stem 41 is the tension spring 44. The plug 43 is provided with the perforations 4.3 in order that the fluid may escape therethrough when the valve is unseated. It will be seen by the foregoing construetion that the valve may be adjusted to vield at any desired pressure from within the stock/T.

. In the. operation of; boring tool, the cutting ends 18 and 19m the jaws 14and 1.3 are first pressed together and then in sorted, into the topaof the well casing. The

tool is then-lowered into the casing by means of the cableB-l until the cutting jaws strike the bottom of-the wells Fluid under pressure is then admitted to thebores 10 and 11 of thestock through theitubing 36, which leads to a source of pressure supply (not shown). Cllhe fluid ithen acts on the piston 29, to force itdownwardly,the conical end 28 thereof Wedging, between the inclined edgesilti andg ofthevja ws. thus causing clearly ihown in Fig. Lof thefirawmg. Power is applied to the oqibl l whereby tli e eutting points of the jaws are 34 to reciprocate the same.

caused to bore the well. the cable being from time to time revolved in order that a round hole may be bored.

\l'hen it is desired to remove the tool from the well. the fluid pressure is released from above by means of a suitable valve (not shown) arranged adjacent the source of supply. The tool is then hoisted upwardly by means of the cable 34. the inclined edges 20 and 21 of the jaws engage with the lower edge of the well cur ng and are forced together thereby. and at the same time the inclined edges 26 and 27 engage with the conical point 2b of the piston 29 and slightly hit the same.

In case that it should prove undesirable to release the pressure from above or that the attendant should fail to do so. the upward movement of the piston 29 will compress the fluid in the stock bore and thereby cause the relief valve 35 to operate to relieve the pressure against the piston.

\Vhat I claim is:

A well boring tool comprising a stock having a hollow bore. a piston mounted in said bore and adapted to slide therein. a plurality of cutting jaws pivoted adjacent the bottom of said stock and adapted to en gage with said piston, means toradinitting fluid under pressure to said hollow bore and behind said piston. and a spring tension alvc in said stock communicating with said hollow bore for automatically relieving the fluid pressure in said bore when said jaws start to contract.

In witness that I claim the foregoing l have hereunto subscribed my name this 15th day of February. 1919.

STEVEN TUlll.

ISIS 

